Apparatus for forming rubber thread



July 26, 1938. 5 'r. 1.. SHEPHERD APPARATUS FOR FORMING RUBBER THREADS Filed March 18, 1936 Patented July 26, 1938 ear s-r r es APPARATUS FOR FORMING RUBBER THREAD Thomas Lewis Shepherd, London, England Application March 18, 1936, Serial No. 69,544 In Great Britain May 15, 1934 Claims.

This invention is a continuation in part to my main application No. 11,720 filed the 18th of March, 1935, and relates to elastic rubber, filamerits, threads or yarns, termed in this specification rubber threads, which are intended to be used in the manufacture of fabric, clothing, lacework and the like or parts thereof or for wearing apparel of any description.

The object of the invention is to provide an improved method and apparatus for forming rubber threads.

The invention will be pointed out in the accompanying claims.

The invention will be described by way of eX- ample with reference to the accompanying drawing, in which:

Figure 1 is a diagrammatic View of the preparation of a thread;

Figure 2 shows the doctor knife, the printing roller, and the belt in longitudinal view, for convenience of illustration not in the same relative position as in Figure 1.

Figure 3 illustrates the formation of other shapes.

In this form a rubber solution or latex is fed from a tank 1 by means of an intermediate roller 2 to a roller I!) which is grooved as shown at H in Figure 2, the cross-sectional size of the grooves of which will correspond with the diameter of the filaments or threads it is desired to produce. The feeding of the solution or dispersion to such a grooved roller i0 is controlled by a doctor blade or member l2 which will remove any excess of solution or dispersion from the circumference of the roller in between the grooves and at the same time will shape the upper surface of the threads which it forms.

The roller I0 is kept in rotation and is arranged adjacent an endless belt l3 passing over a roller I l, such belt being designed to have line contact with the roller H] as shown so as to remove therefrom and carry forward continuous filaments or threads of solution or dispersion from the tank y, carried in each groove in the roller so that the filaments or threads may be said to be printed upon the moving belt. The threads pass on to an endless belt or on to a belt in the form of a band of paper or other material between the roller and endless belt and in that way be brought adjacent to a suitable heating apparatus or over steam heated cylinders so as to dry the threads. The full cross section of a thread is formed partly by the cross-sectional form of the recesses or grooves II and partly by complementary recesses or notches in the doctor blade as indicated at I5 in Figure 2. The roller may be constructed to have a plain surface.

The shapes of the recesses or grooves in the doctor blade and, if grooves are provided, in the roller are arranged to suit requirements, and I have found that a variety of shapes may be produced by these means.

Two of such shapes may be inferred by reference to Figure 3, which shows how an octagonal section thread may be produced, and also a 10 thread half of which is semicircular, the other half triangular. Threads of various shapes may be formed for the purpose of increasing the grip which covering windings will have upon it, and also, when the threads are not covered, of lessen- 15 mg the slip between thread and fabric.

By using an intermediate roller I find that the supply of latex or rubber solution to the main roller may be arranged to approximate to requirements, and that it has advantages in this respect 20 over running the main roller itself dipping in the solution, especially when the intermediate roller is doctored, for instance as shown by the doctor it in Figure 1.

The threads of rubber solution or latex are carried by the belt and solidified by the usual methods, that is, in the case of either rubber solution or latex, by a drying process or, in the case of latex, by a coagulating process. They are then separated from the belt and treated or used as 0 desired. The threads in the example pass on to a belt upon which they are rendered solid by coagulation or drying or both. It is possible however to coagulate or dry or both upon the roller.

The rubber or latex solution used is a solution of rubber or an aqueous dispersion of rubber particles and the consistency must be such that the threads retain their shape on the belt and on the roller, except when influenced by the doctor blade or blades.

The rubber solution or latex may be formed into threads by a doctor by being applied to a moving belt and being moved past a stationary doctor which is provided with recesses. In such a case the belt may also be provided with re- 5 cesses, The doctor and grooves in the upper part of Figure 2 might serve to illustrate this, since the cross section of the thread would be formed in an analogous manner.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is 1. Apparatus for forming rubber thread, consisting of a rotating roller, a stationary recessed doctor adjacent said roller, means for applying fluid consists of a further roller, and in which the first mentioned roller has grooves which register with the recesses in the doctor.

5. Apparatus for forming rubber thread, consisting of a moving surface, a groove on said surface for shaping the under side of the thread, a stationary doctor adjacent to the path of said surface and contacting with said surface on both sides of the groove, and a recess in said doctor for shaping the upper side of the thread.

THOMAS LEWIS SHEPHERD. 

